Late detection and drug resistance have maintained the grim statistics for ovarian cancer (OvCa) steady over decades. New approaches using combination therapies with mechanistically distinct components are hypothesized to be most effective. The long term goal of this research is to develop, integrate and validate key platform technologies to screen mechanism-based combination regimens with photodynamic therapy (PDT) for residual and recurrent OvCa. Heterocellular 3D printed tumor arrays that incorporate critical determinants of OvCa biology (endothelial and mesothelial cells with macrophages and fibroblasts) along with hyperspectral microscopy for simultaneous quantitative imaging of multiple biomarkers will provide exceptional insight into OvCa growth and treatment response on a high throughput platform. To address the grueling toxicities and frequent recurrence that cause OvCa-related deaths, we leverage our nanotechnology program to fabricate nanoconstructs for intracellular delivery of targeted inhibitors, and deliver rational combination regimens with PDT, an FDA approved photochemistry-based treatment that has shown clinical promise for OvCa. PDT is effective on chemo and radiation resistant cells and synergizes with chemotherapeutic and biologic agents resulting in improved efficacy. Treatment results optimized in the heterocellular 3D arrays will be rigorously validated in vivo and in ex vivo patient tissue-derived 3D cultures to demonstrate the predictive capabilities of the bio- and imaging-based screening platform. The goals will be realized in 3 specific aims: 1) Develop and characterize heterocellular 3D printed tumor arrays for micrometastatic OvCa, and nanoconstructs for intracellular delivery of therapeutic agents. 2) Deploy heterocellular tumor arrays for assessment of cytotoxic and molecular responses to a two-tiered therapeutic approach- i) first-line PDT + chemotherapy of residual disease followed by ii) second-line treatment of chemoresistant recurrent disease with PDT + targeted biological therapies. 3) Validate treatment response of 3D tumor arrays in vivo, and in ex-vivo tissue derived cells in 3D culture. Major deliverables of this proposal will be i) Heterocellular 3D OvCa tumor arrays and nanoconstructs for multi-agent intracellular delivery, ii) Optimal combination delivery strategies and conditions to mitigate regrowth, and iii) Rigorous validation of the heterocellular tumor array data in the context of both a clinically-relevant murine model for metastatic OvCa, and in patient tissue-derived 3D cultures. The findings from this study will impact outcomes for patients with advanced (stage II-IV) and resistant OvCa and those receiving salvage therapy. The infrastructure developed through this highly integrated approach will create a new framework to rapidly evaluate and optimize new therapeutic strategies that will be adaptable to a broad array of metastatic tumors and molecular targets. Because molecular expressions and responses can be idiosyncratic, the proposed rapid monitoring of biomarkers expression and treatment-induced biomarkers changes creates the possibility of patient-customized treatments in the future.